Many types of planetary gearsets of single-element or also multi-element planetary transmissions are known. For the lubrication and cooling of the planetary gearwheels of individual planetary gearsets it is generally provided that the bolts of the planetary gearwheels each have lubricant bores—usually a central bore and one or more radial bores—so that lubricant can be fed via these lubricant bores both to the mounting bearings and to the teeth of the planetary gearwheels concerned. For this purpose the lubricant supplied by a hydraulic system is usually fed, via a central shaft of the planetary transmission and suitably located radial holes in the said central shaft, into an area close to the individual planetary gearsets, preferably an area immediately adjacent to the planetary gearset concerned, in such manner that as a result of centrifugal force action the lubricant can flow axially past the planetary gearset in question in the radial direction. To retain this radially flowing or spraying lubricant in the area of the bolts of the respective planetary gearset, lubricant baffles are usually provided, which are usually attached to the satellite carrier of the planetary gearset concerned. The lubricant so retained then passes in a simple way into the lubricant bores of the bolts of the respective planetary gearset under centrifugal action, and is then distributed to the mounting bearings and teeth of the planetary gearwheels. An example of an arrangement for the lubrication and cooling of a planetary gearset made in such a way according to the prior art is shown in FIG. 1, in which the path of the lubricant feed is indicated as A.
However, the lubricant baffles can also be arranged on a structural element immediately adjacent to the satellite carrier, leaving only a small axial gap between the lubricant baffle and the satellite carrier.
Such arrangements for the lubrication and cooling of individual planetary gearsets are also known in combination with various gearset concepts in multi-stage planetary transmissions. For example, U.S. Pat. No. 6,120,410 discloses a sectional view of a 6-gear automatic transmission with several planetary gearsets, each having a lubricant baffle attached on its satellite carrier.
A disadvantage of these arrangements known from the prior art for lubricating and cooling the planetary gearwheels of single-element or multi-element planetary gearsets, besides having to provide the lubricant baffles as additional structural elements, is also the cost and effort of machining the respective structural elements to which the lubricant baffles have to be attached securely under rotational load, as well as the cost and effort of fitting the lubricant baffles.
The purpose of the present invention is now, starting from the aforesaid prior art, to provide a planetary transmission with at least one single-element or multi-element planetary gearset and a simple, assembly-friendly and inexpensive lubrication system for the planetary gearwheels of the planetary gearset.